…Innodb_truncated_status_writesblogpercona.commanual innodb_use_native_aioblogpercona.commanual innodb_use_sys_mallocblogpercona.commanual innodb_versionblogpercona.commanual innodb_write_io_threadsblogpercona.commanual insert…
Post: InnoDB: look after fragmentation
November 5, 2009 By 12 Comments
… was slow. How slow ? Let me show. The query in question is (Q1): SELECT count(…inserted not in order. +—————————+ | count(distinct username) | +—————————+ | 5903053 | +—————————+ 1 row in set (2 min 8.92 sec) mysql> SHOW STATUS LIKE ‘Innodb…
Post: How innodb_open_files affects performance
November 18, 2009 By 4 Comments
…innodb_open_files does not affect performance a lot on reads – what is about writes ? I tried again very simple test inserting… as with select case I could not see any measurable difference between two tested innodb_open… is no any surprises such as surprised slow downs for replacing open files in the…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
…be free already. OS Waits are relatively slow, and if you get tens of thousands…InnoDB 442 mysql tables in use 1, locked 0 MySQL thread id 8079, query id 728899 localhost root Sending data select…number of inserts is pretty much insert buffer efficiency. Adaptive hash index is hash index Innodb builds…
Post: My Innodb Feature wishes
May 4, 2006 By 30 Comments
…Insert buffer for delete. For Insert operation Innodb uses nice tecnique called Insert Buffer which speeds up inserts…same row is going to be slow. For medium sized blobs it …select not to cluster by it instead of creating fake primary key and promoting real one to unique. Tablespaces. To call “innodb…
Post: Heikki Tuuri answers to Innodb questions, Part II
November 4, 2007 By 13 Comments
…or can a bit slow it down. Plus there were bunch of micro optimizations in Innodb in 5.0 …! If you have inserted in an ascending order of the PRIMARY KEY, then InnoDB should have placed the… showed up in “show innodb statusâ€. select * from table where id=5 show innodb status: Hash table size …
Post: The perils of InnoDB with Debian and startup scripts
January 28, 2009 By 13 Comments
…select … | 6360 | user | | NULL | 6361 | user | | NULL +——+——————+—————-+————- Notice all those processes in ‘statistics’ status. Why is that happening? Look at SHOW INNODB…
Post: Reasons for run-away main Innodb Tablespace
June 10, 2010 By 1 Comment
…Innodb Tablespace. Insert Buffer size is also restricted to half of the buffer pool size (can be changed via innodb…re running very long transaction, be it even SELECT, Innodb will be unable to purge records for … you can use innodb_max_purge_lag to make a threads doing modifications slow down if …
Comment: Why MySQL could be slow with large tables ?
January 31, 2008 By 139 Comments
… particular table (in context), since SELECTing data is always faster then INSERTing it. The table spec is the… DELETE NO ACTION ON UPDATE NO ACTION ) ENGINE=InnoDB; The capital letters are INDEXes and some …consideration what I want from it?! Could the INSERTs be slow, dued to the size of the PRIMARY…
Post: Thinking about running OPTIMIZE on your Innodb Table ? Stop!
December 9, 2010 By 13 Comments
… lot better fill factor. The problem is…. OPTIMIZE TABLE for Innodb tables does not get advantage of it for whatever reason… KEY (`id`), KEY `c` (`c`) ) ENGINE=InnoDB AUTO_INCREMENT=12582913 DEFAULT CHARSET=latin1 mysql> select * from a order by id limit 10…) do not get advantage of it and will use old slow method of building indexes by insertion.
